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Purpose Children with comorbidities have a higher risk of severe, coronavirus disease 2019 (COVID-19). This study investigated the clinical features and outcomes of COVID-19 in children and adolescents with diabetes between January and March 2022. Methods We retrospectively reviewed the medical records of 123 children and adolescents (73 with type 1 diabetes and 50 with type 2 diabetes, 59 males and 64 females) aged

With the continuously growing requirement for encryption in network environments, web browsers are increasingly employing hypertext transfer protocol security. Despite the increase in encrypted malicious network traffic, the encryption itself limits the data accessible for analyzing such behavior. To mitigate this, several studies have examined encrypted network traffic by analyzing metadata and payload bytes. Recent studies have furthered this approach, utilizing graph neural networks to analyze the structural data patterns within malicious encrypted traffic. This study proposed an enhanced encrypted traffic analysis leveraging graph neural networks which can model the symmetric or asymmetric spatial relations between nodes in the traffic network and optimized feature dimensionality reduction. It classified malicious network traffic by leveraging key features, including the IP address, port, CipherSuite, MessageLen, and JA3 features within the transport-layer-security session data, and then analyzed the correlation between normal and malicious network traffic data. The proposed approach outperformed previous models in terms of efficiency, using fewer features while maintaining a high accuracy rate of 99.5%. This demonstrates its research value as it can classify malicious network traffic with a high accuracy based on fewer features.

Abstract In this study, we experimentally demonstrate fabrication of ultra-smooth and crystalline barium titanate (BTO) films on magnesium oxide (MgO) substrates by engineering lattice strain and crystal structure via thermal treatment. We observe that oxygen-depleted deposition allows growth of highly strained BTO films on MgO substrates with crack-free surface. In addition, post-thermal treatment relaxes strain, resulting in an enhancement of ferroelectricity. Surface roughening of the BTO films caused by recrystallization during post-thermal treatment is controlled by chemical–mechanical polishing (CMP) to retain their initial ultra-smooth surfaces. From Raman spectroscopy, reciprocal space map (RSM), and capacitance–voltage (C–V) curve measurements, we confirm that the ferroelectricity of BTO films strongly depend on the relaxation of lattice strain and the phase transition from a-axis to c-axis oriented crystal structure.

We investigated the defect states and optoelectrical properties of methylammonium lead iodide (MAPbI3) perovskite films synthesized via a two-step dry process. To synthesize MAPbI3 thin films, PbI2 thin films were deposited via rf magnetron sputtering and were subsequently exposed to methylammonium iodide (MAI) vapor to synthesize MAPbI3 thin films. By using deep level transient spectroscopy and space-charge-limited current methods, the defect density of the perovskite films was proven to be reduced by about 6 times as the reaction temperature increased from 90 to 110 °C. At a high reaction temperature of 130 °C, the deformation process could occur, resulting in a rising trap density within the perovskite film. Along with a significant decline in defect density, the photoresponsivity of films fabricated at 110 °C were higher by about 2.05 and 18.76 times more than those of samples prepared at 100 and 130 °C, respectively. An excellent detectivity of 1.17 × 1013 Jones was observed from the sample synthesized at 110 °C, demonstrating the superiority of a two-step dry process.

Abstract Post-menopausal depression (PMD) is a common psychological disorder accompanied by a cognitive deficit, which is caused by a series of uncontrolled emotional disruptions by strong environmental stressors during menopause. To overcome PMD-induced cognitive deficit, Green tea has been suggested as a dietary supplement because of its ameliorating effect on cognitive dysfunction induced by normal aging or neurodegenerative syndromes; however, its clinical use to improve PMD-accompanied cognitive deficit is still limited due to the controversy for the active ingredients and ambiguous mechanism of its action. Here, we developed modified high-temperature-processed green tea extract (HTP-GTE), which showed lower neuronal toxicity than the conventional green tea extract (GTE). We also demonstrated that HTP-GTE administration prevented the development of learned helplessness (LH) in a rat post-menopausal model. Additionally, HTP-GTE improved LH-induced cognitive impairments simultaneously with rescued the long-term synaptic plasticity. This occurred via the restoration of silent synapse formation by increasing the hippocampal BDNF-tyrosine receptor kinase B pathway in the helpless ovariectomized (OVX) rats. Likewise, we also identified that (−)-gallocatechin gallate was the main contributor of the HTP-GTE effect. Our findings suggested that HTP-GTE has a potential as a preventive nutritional supplement to ameliorate cognitive dysfunctions associated with PMD.

Aging leads to cognitive impairments characterized by reduced hippocampal functions that are associated with impairment of long-term potentiation of CA1 synapses. Here, we assessed the safety and efficacy of modified (−)-gallocatechin gallate (GCG)-enriched green tea extract (HTP-GTE) in ameliorating the cognitive dysfunctions in late middle-aged murine model. We developed a novel HTP-GTE that was enriched with GCG via epimerization that involved heating. We compared the effects of oral administrations of conventional green tea and HTP-GTE in young and aged male C57/BL6 mice, and examined the changes in the hippocampal functions related to aging process. The functional outcome was assessed by the electrophysiological experiments to measure the long-term potentiation (LTP). HTP-GTE improved the age-related cognitive impairments via restoring long-term synaptic plasticity. We also identified that GCG was the main active component responsible for the HTP-GTE effect. The main molecular pathway in ameliorating the age-related cognitive dysfunctions involved protein kinase A (PKA) which was shown to be modulated by HTP-GTE. Thus, HTP-GTE has a therapeutic potential as a dietary supplement which may aid to rescue the impaired cognitive functions at the early phase of aging process through the modulation of LTP threshold.

Background : Adiposity may play a role as a potential trigger for adrenarche. The purpose of this study was to evaluate the association between body mass index (BMI) and serum dehydroepiandrosterone sulfate (DHEAS) level. Methods : The medical records of 8-year-old girls who presented to our clinic between 2014 and 2016 with concerns regarding pubertal changes were retrospectively reviewed. The 192 girls were divided into two groups depending on activation of the hypothalamic-pituitary-gonadal (HPG) axis. Group I included 77 subjects with a breast Tanner stage 1 with unknown HPG axis or thelarche without activated HPG axis. Group II included 115 subjects with activated HPG axis. Serum DHEAS level ≥1.1 μmol/L was regarded as biochemical adrenarche. Results : Based on correlation analyses, BMI standard deviation score (SDS) was positively correlated with height SDS, bone age divided by chronological age (BA/CA), and DHEAS level in all subjects (r=0.269, r=0.270, r=0.298; all P

Recent work has shown that thalamocortical (TC) inputs can be plastic after the developmental critical period has closed, but the mechanism that enables re-establishment of plasticity is unclear. Here, we find that long-term potentiation (LTP) at TC inputs is transiently restored in spared barrel cortex following either a unilateral infra-orbital nerve (ION) lesion, unilateral whisker trimming, or unilateral ablation of the rodent barrel cortex. Restoration of LTP is associated with increased potency at TC input and reactivates anatomical map plasticity induced by whisker follicle ablation. The reactivation of TC LTP is accompanied by reappearance of silent synapses. Both LTP and silent synapse formation are preceded by transient re-expression of synaptic GluN2B-containing N-methyl-D-aspartate (NMDA) receptors, which are required for the reappearance of TC plasticity. These results clearly demonstrate that peripheral sensory deprivation reactivates synaptic plasticity in the mature layer 4 barrel cortex with features similar to the developmental critical period.

We are developing a practical-scale mechanical decladder that can slit nuclear spent fuel rod-cuts (hulls + pellets) on the order of several tens of kgf of heavy metal/batch to supply UO2 pellets to a voloxidation process. The mechanical decladder is used for separating and recovering nuclear fuel material from the cladding tube by horizontally slitting the cladding tube of a fuel rod. The Korea Atomic Energy Research Institute (KAERI) is improving the performance of the mechanical decladder to increase the recovery rate of pellets from spent fuel rods. However, because actual nuclear spent fuel is dangerously toxic, we need to develop simulated spent fuel rods for continuous experiments with mechanical decladders. We describe procedures to develop both simulated cladding tubes and simulated fuel rod (with physical properties similar to those of spent nuclear fuel). Performance tests were carried out to evaluate the decladding ability of the mechanical decladder using two types of simulated fuel (simulated tube + brass pellets and zircaloy-4 tube + simulated ceramic fuel rod). The simulated tube was developed for analyzing the slitting characteristics of the cross section of the spent fuel cladding tube. Simulated ceramic fuel rod (with mechanical properties similar to the pellets of actual PWR spent fuel) was produced to ensure that the mechanical decladder could slit real PWR spent fuel. We used castable powder pellets that simulate the compressive stress of the real spent UO2 pellet. The production criteria for simulated pellets with compressive stresses similar to those of actual spent fuel were determined, and the castables were inserted into zircaloy-4 tubes and sintered to produce the simulated fuel rod. To investigate the slitting characteristics of the simulated ceramic fuel rod, a verification experiment was performed using a mechanical decladder.

We have developed a practical-scale dry disassembling process to dismantle PWR (Pressurized Water Reactor) spent nuclear fuel assembly in the order of several tens of kilograms of heavy metal/batch to supply rod-cuts (cladding tube and UO2 pellets) for mechanical decladding process. Dry head-end disassembling process has advantages over the wet head-end process because of the lower risk of proliferation and treatment of spent fuel with relatively high heat and radioactivity. This study describes the main design considerations for the disassembling process of the spent nuclear fuel assembly during the dry head-end process. The down-ender, dismantling, extraction, and cutting technologies are analyzed and models have been designed for testing. The purpose of dry head-end disassembly process is to test the main device performance and to obtain scale-up data for practical-scale disassembling. With this in mind, design considerations were analyzed based on remoteness, and basic verification tests were performed. However, the authors used simulated fuel, instead of the actual spent fuel, owing to a lack of joint determination. In addition, in the present study, we did not consider the heat generated from minor actinides or the radioactivity of the fission product; these aspects will be considered in a future study. During the basic test performed in this study, a simulated assembly was completely disassembled using new methods, such as dismantling, extraction, and cutting processes. The practical-scale dry disassembling technology can be tested using scale-up data for reuse of the spent fuel.

A practical scale mechanical decladder that can slit spent nuclear fuel rod-cuts (hulls + pellets) of several tens of kg HM/batch is being developed to supply UO2 pellets to a voloxidation process. The mechanical decladder is an apparatus for separating and recovering fuel material and cladding tubes by horizontally slitting the cladding tube of a fuel rod and a defective irradiated fuel rod. In this study, we address the engineering design of the mechanical decladder for the pretesting of rod-cut slitting. To obtain the requirements of the mechanical decladder, we first manufactured a slitter for testing based on the decladding and shearing conditions of hulls and pellets. The performance test of the testing device for decladding was carried out using a 2-CUT blade module and a 3-CUT blade module. We evaluated the decladding methods for the mechanical decladder and selected the 3-CUT blade module based on the results. A buckling measurement instrument was used to perform a buckling verification test according to the length of a rod-cut and to determine decladder dimensions. The optimum decladding rod-cut length for buckling prevention was calculated. Furthermore, we analyzed the decladding mechanism for various slitting methods. Design/fabrication and preliminary tests of the practical scale mechanical decladder were also performed. For this purpose, we constructed the main mechanism by utilizing the SolidWorks modeling and analysis program and fabricated a new mechanical decladder. Based on the derived requirements, a mechanical decladder with three main modules was designed and fabricated for testing. Simulated rod-cuts of zircaloy were also manufactured to test the basic performance of the decladder, and a data acquisition system was constructed using RSC 232 to measure decladding force and velocity. In the basic test, the rod-cut was completely sectioned into three evenly spaced locations by the new mechanical decladder.

The purpose of this study is to develop a solid dispersion system with improved dissolution, absorption, and patient compliance of poorly water-soluble celecoxib (CXB). Instead of sodium lauryl sulfate (SLS), an anionic surfactant used in the marketed product (Celebrex®), solubilization was performed using non-ionic surfactants with low toxicity. Cremophor RH40 (Cre-RH) was selected as the optimal solubilizer. Granules and tablets containing CXB and Cre-RH were prepared via fluid-bed and tableting processes, respectively. The morphology, crystallinity, flowability, dissolution, and pharmacokinetics for CXB-solid dispersion granules (SDGs) and the hardness and friability for CXB-solid dispersion tablets (SDTs) were evaluated. The solubility of CXB was found to be increased by about 717-fold when using Cre-RH. The dissolution of granules containing Cre-RH was found to be increased greatly compared with CXB API and Celebrex® (66.9% versus 2.3% and 37.2% at 120 min). The improvement of the dissolution was confirmed to be the same as that of granules in tablets. The CXB formulation resulted in 4.6- and 4.9-fold higher AUCinf and Cmax of CXB compared with those of an oral dose of CXB powder in rats. In short, these data suggest that the solid dispersion based on Cre-RH—a non-toxic solubilizer, non-ionic surfactant— may be an effective formulation for CXB to enhance its oral bioavailability and safety.

A voloxidizer with a double reactor capable of processing several tens of kilograms of HM/batch of nuclear spent fuel has been developed for the decladding and voloxidation of rod-cuts into hulls and pellets through the conversion of UO2 pellets to U3O8 powder. In this study, we optimized the engineering design of this voloxidizer to improve its hull-recovery ratio. First, we tested the oxidation performance of the device prototype and evaluated the effectiveness of various mechanical and chemical voloxidizing methods. On the basis of the results, we selected the screw-and-rotation method for the double rotary drum. Next, we derived a theoretical equation for calculating the optimal reactor volume for various rod-cut weights and lengths and then validated the equation using centimeter-scale acryl reactors and hulls. Subsequently, we modularized the main components such as the heater, utility, motor, reactor, valve, and structure. The double reactor was subject to preliminary separation tests of hulls and powder. Moreover, the hull-separation performance of the voloxidizer reactor was tested at a loading of 50 kg HM/batch. Finally, the remote assembling and disassembling possibility of the modules were experimentally optimized.

Palladium (Pd)-based hydrogen (H2) gas sensors have been widely investigated thanks to its fast reaction and high sensitivity to hydrogen. Various sensing mechanisms have been adopted for H2 gas sensors; however, all the sensors must be powered through an external battery. We report here an H2 gas sensor that can detect H2 by measuring the output voltages generated during contact electrification between two friction surfaces. When the H2 sensor, composed of Pd-coated ITO (indium tin oxide) and PET (polyethylene Terephthalate) film, is exposed to H2, its output voltage is varied in proportion to H2 concentration because the work function (WF) of Pd-coated surface changes, altering triboelectric charging behavior. Specifically, the output voltage of the sensor is gradually increased as exposing H2 concentration increases. Reproducible and sensitive sensor response was observed up 1% H2 exposure. The approach introduced here can easily be adopted to development of triboelectric gas sensors detecting other gas species.

In the rapidly evolving healthcare environment, radiologists strive to establish their rightful place. Thus, there is a need for enhanced outpatient and clinical education within the Department of Radiology and exploration of its methodologies. Accordingly, the Korean Society of Radiology established a task force to investigate the clinical and outpatient practice status of radiologists overseas, current state of related education, involvement of other specialties in radiologic practices and education in Korea, and clinical and outpatient practice status among Korean radiologists. Furthermore, a survey on clinical competency enhancement was conducted among the members of the Korean Society of Radiology. These findings suggest the need for visibility and clinical competency enhancement in radiologists and methodologies for strengthening clinical competencies. [ABSTRACT FROM AUTHOR]

Aortic anastomotic leak is an uncommon complication after ascending aortic replacement for acute aortic dissection. Redo-surgery is the traditional standard treatment despite high mortality and morbidity. Recently, endovascular treatment has been attempted as an alternative approach in a few case reports. Here, we present two cases of aortic anastomotic leak due to suture line dehiscence after aortic graft replacement for type A aortic dissection, which were successfully treated by coil with subsequent N-butyl cyanoacrylate embolization and an AmplatzerTM vascular plug. [ABSTRACT FROM AUTHOR]